Nicolaus Copernicus: Life, Heliocentrism, and Legacy

Background and Education

The Polish astronomer Nicolaus Copernicus is most famous for his thesis that the sun, rather than the earth, forms the center of the universe. Born on 19 February 1473 in the West Prussian city of Toruń, to Barbara Watzenrode and Nicolaus Copernicus Senior — a wealthy copper merchant — he was the youngest of four siblings. To be precise, Copernicus hailed from a German-speaking culture, given his birthplace at the time and his first language, German. However, some historians claim he also knew Polish. Sometime after he turned ten, Nicolaus lost his father. Lucas Watzenrode, the Varmian Bishop and his mother's brother, then raised him. In 1491, Copernicus enrolled at the University of Cracow to study mathematics and painting. It was there that he began to develop an interest in astronomy and started collecting works on the subject.

Established as Canon

By the mid-1490s, Copernicus was appointed as a canon at Frombork Cathedral, a post he retained throughout his life. This proved to be a fortunate development: the clergy position helped him finance his education and research for the remainder of his days. In 1496, he traveled to Italy and enrolled in a religious law course at the University of Bologna. It was there that his momentous meeting with the astronomer Domenico Maria Novara took place. The two began exchanging theories and notes on astronomy and eventually became housemates.

In 1501, Copernicus enrolled at the University of Padua to study practical medicine. However, because his two-year absence threatened the expiration of his clergy position, he did not complete his medical degree. Two years later, he enrolled at the University of Ferrara, completed the required examinations for a doctoral degree in canon law, and quickly returned home to resume his canon duties. He recommenced residence at Lucas Watzenrode's Episcopal castle in Lidzbark-Warminski for many years, during which time he pursued his astronomy studies and cared for his aging and ailing uncle. In 1510, he relocated to a residence at Frombork Cathedral, where he remained until his death.

The Heliocentric Solar System

Copernicus continued his astronomy studies throughout all the years he lived with his uncle. According to researchers, he had already begun developing his celestial heliocentric model of the solar system by around 1508. In the second century, Ptolemy had proposed a geometric model of planetary motion featuring eccentric epicycles and circular orbits — a view markedly different from Aristotle's premise that planets and other celestial bodies revolve around the Earth along constant circular paths. In a bid to resolve these discrepancies, Copernicus, in his heliocentric model, placed the sun — not the earth — at the center of the universe. According to his model, the speed and size of individual planetary orbits depended on how far each planet was located from that center.

While scholars of the era found his ideas revolutionary, the model sparked considerable debate. Nonetheless, Copernicus's heliocentric model was the most precise and comprehensive framework proposed to that point, and included a more effective formula for calculating the positions of planets. He argued that, if the sun were stationary and the earth in motion, the other planets would fall into a well-ordered relationship in which their sidereal periods increase with distance from the sun: Mercury completes its revolution in 88 days; Venus in 225 days; the Earth in one year; Mars in 1.9 years; Jupiter in approximately 12 years; and Saturn in roughly 30 years. This effectively resolved the longstanding conflict regarding planetary order.

In 1513, Copernicus's dedication led him to build a modest independent observatory. His observations occasionally produced erroneous conclusions — for instance, his initial assumption that planetary orbits were perfectly circular. It was not until the seventeenth century that Kepler proposed the concept of elliptical planetary orbits.